1. Field of the Invention
The present invention relates to a method for detecting tracks of touch inputs on a touch-sensitive panel, and more particularly, to a method for detecting tracks of multi-touch inputs on the touch-sensitive panel in order to accurately determine operating gestures of users.
2. Description of the Prior Art
As for a traditional capacitive touch-sensitive panel or an optical touch-sensitive panel, its processor detects touch inputs on the touch-sensitive panel based on a predetermined scanning sequence. When a touch input is detected, the processor stores the corresponding coordinate value of the position of the touch input located on the touch-sensitive panel into an array of a memory. For example, assume that the processor scans the touch inputs of the whole touch-sensitive panel row-by-row from the upper-left to the lower-right of the touch-sensitive panel. As a result, the corresponding coordinate value of a first scanned touch input is recorded into a first position of the array, the corresponding coordinate value of a second scanned touch input is recorded into a second position of the array, and so on.
However, since the sequence for storing the coordinate values of the array is determined according to the detected sequence of the corresponding touch inputs on the touch-sensitive panel, the processor may make wrong judgments for some specific gestures when the user utilizes multiple fingers moved on the touch-sensitive panel. As an illustration, please refer to FIG. 1. FIG. 1 (including (1a) and (1b)) is a diagram showing a user uses his thumb and index finger to make a rotation track on a touch-sensitive panel 100. First, as (1a) of FIG. 1 depicts, assume that the processor scans the touch inputs of the whole touch-sensitive panel 100 row-by-row from the upper-left to the lower-right of the touch-sensitive panel 100. Therefore, a first position of an array 110 is used for recording the coordinate value P1 corresponding to the position of the thumb on the touch-sensitive panel 100, and a second position of the array 110 is used for recording the coordinate value P2 corresponding to the position of the index finger on the touch-sensitive panel 100. Afterwards, as (1b) of FIG. 1 depicts, when the user uses his thumb and index finger to make a rotation track along the dotted line on a touch-sensitive panel 100, such that the thumb and the index finger of the user are moved to the positions shown in (1b). At this time, a first position of an array 120 is used for recording the coordinate value P2′ corresponding to the position of the index finger on the touch-sensitive panel 100, and a second position of the array 120 is used for recording the coordinate value P1′ corresponding to the position of the thumb on the touch-sensitive panel 100. Since the processor determines the tracks of the touch inputs by reference to the positions of the arrays, the processor may erroneously determines that the coordinate value P2′ recorded in the first position of the array 120 corresponds to the coordinate value of the thumb (actually, it should correspond to the coordinate value of the index finger), and the processor may erroneously determines that the coordinate value P1′ recorded in the second position of the array 120 corresponds to the coordinate value of the index finger (actually, it should correspond to the coordinate value of the thumb). For these reasons, the processor may erroneously determine the tracks of the user's fingers on the touch-sensitive panel 100, and is unable to accurately determine operating gestures of the user.